The present invention relates to a rotor for a hammer mill or crusher, for example for breaking-up, shredding, or otherwise reducing the size of scrap, household and industrial refuse, etc.
The material, such as scrap or refuse, that is to be broken up with a hammer mill can have practically any geometric shape and composition. For example, the material can include previously compressed automobile bodies, refrigerators, washing machines, stoves, metal containers, sheet metal items, sheet metal strips, etc. As great a throughput as possible is attempted to be achieved by a suitable arrangement of the arms, and hence of the hammers, in the rotor.
It is known to assemble the rotors for hammer mills for breaking-up scrap or other material of two-part or multi-part arms that are disposed next to one another. If double-ended arms are used, they are staggered by 90.degree. (U.S. Pat. No. 3,844,494) Hightower dated Oct. 29, 1974, while multi-part arms have stars with three or six arm ends that are disposed in a single plane and are distributed uniformly over the periphery of the rotor.
The drawback with the heretofore known shapes and arrangements of the rotor arms is that the ends of the arms generally have only a small crosssectional area, so that the rotor therefore has only a relatively small moment of inertia. In addition, disposed between these arms are large spaces in which scrap or other material can accumulate. Due to the low moment of inertia, and the material that accumulates, the rotor becomes out-of-balance and operates noisily, the speed falls off, and the rotor can also become jammed and can be prevented from operating.
It is therefore an object of the present invention to embody a rotor of the aforementioned general type in such a way that at prescribed dimensions for the rotor, as great a moment of inertia as possible is achieved, the danger of having material accumulate in the spaces between the support elements is greatly reduced, and a good adaptability to the material that is being brokenup at any given time is provided.